Gallery

Photos take a lot of disk space and bandwidth, not all of us have that
available on a web server.

If Gallery supported integrating with Amazon's S3 via a plugin that used a
storage API, gallery users would have unlimited storage (at a price).

They would be stored on amazon's servers, and optionally served off of
them, or (optionally) off the server, using a user configurable cache
size.

The end result would be tons of storage and bandwidth regardless of what
your server has. No need to worry about some growth.

Amazon's S3 is also redundant, so your photos are likely safer than if you
hosted them yourself.